Alarm for patient monitor and life support equipment system

ABSTRACT

An alarm system for notifying necessary medical and hospital personnel that a patient or the patient&#39;s life support equipment require immediate response without providing the alarm signal to the monitored patient or surrounding patients, to prevent patient trauma which may otherwise result from the sound of the alarm. The system includes an alarm signal generator that provides a coded pulse indication of the patient and equipment type. The coded signal is sent to a master control unit preferably located at a nurses&#39; station. The master control unit then transmits the coded alarm signal simultaneously to the appropriate group of pagers having vibrational annunciators and a visual display that describes the patient location and equipment type. The patients monitor and equipment at bedside and the pagers have no audio alarm signals. The alarm signal can only be terminated manually by an interrupt switch at the bedside.

This application is a continuation-in-part of application Ser. No.07/666,266, filed Mar. 6, 1991, abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to a communications and alarm systemfor providing secure and reliable patient monitoring and also formonitoring the operational status of various types of medical equipmentsuch as, but not limited to, intravenous feeding devices,defibrillators, ventilators, EKG, EEG and pulse monitors. The equipmentused with the present system includes emergency equipment employed in apre-hospital setting, such as in ambulances or at the site of accidents;equipment in post-hospital settings, such as in a patient's home, in anursing home, in a hospice, in a Doctor's office, in a clinic or atmedical teaching institutions and equipment used in the hospital such asin the recovery room or in the operating room.

The invention is capable of providing a means for communicating medicalinformation over long distances and for immediately summoning theappropriate medical and hospital personnel to the patient in need ofhelp. The invention is silent and unobservable to the patient to preventunnecessary stress or trauma. The system can also reduce the stresslevel of the medical and hospital staff and other patients. Anotheraspect of the present invention is to provide monitoring equipment thatcan be conveniently worn on medical personnel in order to fostercommunications that indicate more information to the user and forhospital administrators. A further aspect of the invention is to providefor a communications system that enables medical personnel to remotelytest the operational status of medical equipment and provide betterstaffing management for medical emergencies communicated by the system.

2. Description of the Prior Art

Critically ill patient and life support equipment monitors and alarmsystems are well known. Typically, the monitor includes an audio alarmlocated next to the patient's bed attached to the patient's life supportmedical equipment. Intravenous (IV) feeders and ventilators are examplesof life support equipment that include an audio alarm if the equipmentshould malfunction or stop completely. The principal problem with thesealarm devices is the stress and trauma that the audio alarm can renderto a critically ill patient. Not only is the audio alarm sound oftenstartling to the patient, but it could also trigger a panic state withcorresponding psychophysiology contributing to or resulting in theinability to marshal an adequate defense against disease.

Examples of intensive alarm systems abound. For example, U.S. Pat. No.4,803,471 shows a ventilator monitor and alarm apparatus issued toRowland on Feb. 7, 1989. U.S. Pat. No. 4,550,726 issued to McEwen onNov. 5, 1985 shows a method and apparatus for the detection of breathinggas interruption typically for a ventilator; U.S. Pat. No. 4,155,375issued to Dahl, May 22, 1979, discloses a patient ventilator disconnectalarm which causes an audible alarm condition; U.S. Pat. No. 3,877,467shows an artificial U.S. Pat. No. 4,316,182 issued to Hodgson Feb. 16,1982 shows a ventilator disconnection alarm. All of these alarm systemsbasically provide for audio and/or visual alarms at the patient'sbedside. Because the sound alert is placed within the hearing range ofthe patient, however, the alarm sound can greatly disturb, if nottraumatize, the patient and, in fact, exacerbate the patient's declinetoward death.

Small pocket sized paging devices which provide audio and tactilevibrational signals to alert the person carrying a pager of a remotecall or message also are known. U.S. Pat. No. 4,879,759 issued toMatsumoto, et al. Nov. 7, 1989, for example, shows a pager with theextra function of a vibrator. Also, U.S. Pat. No. 4,918,438 shows apaging receiver having an audible and a vibrator annunciating meansissued to Yamasaki, Apr. 17, 1990. U.S. Pat. No. 4,786,889 issued toHayasaka shows a battery casing for a paging receiver which includes avibrating housing for alerting someone through a pager without audiblesound. U.S. Pat. No. 4,794,392 issued to Selinko on Dec. 27, 1988,describes a vibrator alert device for a communication receiver, which isessentially a paging device.

Although the prior art paging equipment does show the use of vibrationwith or without an audio sound, heretofore such paging equipment doesnot function in combination with a communications system linked tomedical equipment to provide a non-audible and more critically,automatic alarm to doctors, technicians and nurses in the patientvicinity without disturbing the patient, and without requiringintermediate action by a paging supervisor to activate pagers inresponse to the alarm.

A further disadvantage of prior art pagers is their limited capabilityfor providing information to the user and for enabling that user torespond quickly and effectively. Typically, pager communications arelimited to providing an audio tone coupled with a lighted display. Thealarm produced by the pager may also contain an image of a phone numberthat the wearer is supposed to call in response to the alarm. Onedrawback to such pagers is that the person wearing the pager is notinformed of the actual nature of the problem until he/she telephones thesender. In those instances where a phone is not readily available to thepaged party, critical response time is lost possibly endangering thepatient's life. Thus, a need exists for a paging device thatcommunicates detailed information about the patient and allows for arapid response by the recipient.

A further disadvantage of conventional pagers is that the informationmust be relayed to the recipient through other personnel. There isthereby some risk that inaccurate information may be conveyed to thedoctor particularly when the medical staff conveying the information isunder pressure and stress. Miscommunication is exacerbated inemergencies, such as "code blue" alerts. A need thereby also exists fora paging system that communicates information directly from criticalmedical equipment to the recipient avoiding the possible delay andmiscommunication by an intermediary.

Conventional pagers also are limited to only receiving messages.However, the message recipient frequently needs to urgently communicateto others. A pager having a two-way communications capability is therebyessential in many emergency situations.

Another drawback of conventional communications devices is the relativeinconvenience of two-way walkie-talkie RF devices used principally byemergency medical technicians to communicate with one another, and withthe hospital emergency room. Typical walkie-talkie arrangements consistof a speaker/microphone attached to a transceiver and power supply whichare all arranged in the same cabinet. The speaker and microphone design,however, has several drawbacks. First, critical messages are oftenrelayed to emergency medical personnel loudly and intrusively causingpossible debilitating distress to the patient. Second, the structuralarrangement of walkie-talkies is inconvenient since the user mustphysically place the walkie-talkie close to his mouth when speaking.Thus, at least one hand is occupied operating the walkie-talkie. In anemergency where the emergency medical technician is under severe timeconstraints to perform CPR or to move an injured person as well ascommunicate with the emergency room, the loss of one hand can be asevere detriment.

Finally, many paging/emergency communications systems fail to coordinateautomatically and flexibly with the variable staffing conditions. Thus,if necessary staff are either not "on call" or are preoccupied withother more urgent medical situations, there is a need to provide afail-safe management device for routing calls to available staff so thatquick responses to medical emergencies can be maximized and so that aresponse is provided to a person in need at all times.

The present invention overcomes the problems of the prior art by acommunications/alarm system for providing secure, efficient and reliablecommunications concerning the medical conditions of patients and thestatus and operational conditions of any medical equipment that may beused in a pre-hospital, post-hospital or in-hospital setting. Thepresent system is designed so that communications do not disturb ortraumatize the patient. Only necessary hospital personnel, such asdoctors, nurses or technicians responsible for the patient and the lifesupport equipment, are alerted. Information is conveyed silently byusing vibration annunciation, specially designed lighted displays, orcommunications devices that have minimum audio warning features.

The displays delineate the specific patient having problems, specificdefective equipment, the patient location and/or designation, theequipment name, or other relevant information read directly off of theequipment. In addition, a communications management system is providedwhich flexibly links hospital staffing circumstances with the medicalneeds of various patients.

SUMMARY OF THE INVENTION

This invention relates generally to a patient monitoring,communications, management and patient life support equipment alarmsystem that is non-audible and unobservable to the patient and that isused to notify doctors, nurses and/or technicians that a patient has amedical problem and/or that medical equipment is malfunctioning. Thesystem can be employed in a pre-hospital, in-hospital and/orpost-hospital setting.

The non-audible communications system in accordance with the inventionis comprised of an electronically actuated signal generator attached toa device sensor(s) connected to any appropriate medical equipment and/orpatient monitoring or operating room equipment, at least one masteralarm control and display unit adapted to communicate with the signalgenerators and/or with other master alarm control units and a centralhost controller. Each master alarm control device can be removed fromthe patient area and located preferably at a nurses' station. In someapplications, the master alarm control can be located in the operatingroom, the emergency room or at any other desired location. Multiplemaster alarm control devices can be tied together in a network. Anappropriate group of pagers that have non-audible annunciators are alsopart of the system.

Each master control and display unit includes suitable logic and memoryto store information concerning the availability of medical staff sothat the master control can manage incoming emergency calls by matchingthose calls with available staff. Typical support equipment to which thecommunications and alarm system is attached include in-hospitalequipment such as IV feeders, ventilators, cardiogram monitors, CO₂machines, fetal monitors, pulse monitors, blood pressure monitors, orother life support, patient monitoring devices or operating roomequipment such as heart/lung machines; pre-hospital equipment used inemergency and non-emergency settings, such as pulse monitors ordefibrillators; and post-hospital equipment used, for example, inpatient's homes, in nursing homes, in hospices, in doctor's offices orin teaching establishments.

Certain life support equipment and patient monitoring equipment demandan immediate response and are of particular concern. A defectiveventilator can immediately stop a patient from breathing. An IV feeder,if interrupted, can be life threatening. Cardiac, pulse and bloodpressure monitoring systems demand immediate responses if the patient isin trouble. The need for immediacy is also critical in an operating roomenvironment where the loss of several seconds may cost a patient's life.The system forming the present invention may also be used to replace oraugment the overhead audio paging system to provide non-audio messagesto summon a particular doctor to a specific destination. Intelligence isprogrammed into the master alarm control part of the system by virtue ofthe logic associated with the master alarm control unit and by virtue ofthe use of a suitable operator who communicates with the medicalpersonnel, the hospital administrators, and most importantly with thepatient to alert appropriate staff based upon changing conditions andpreferences.

The alarm component of the invention comprises an alarm signal generatorthat receives electrical output signals from a conventional equipmentalarm sensor(s) which is non-audible indicating that a patient is introuble or equipment is defective or shut down. The alarm signalgenerator has its own power source and is in communication with themaster control and display unit or units.

The alarm signal generator transmits a coded pulse signal in response toa sensor(s) signal indicating a problem and provides variousidentification information such as particular patient and/or equipmenttype and location for display on the master control and display unit.Immediate transmission from the master unit or units then occurs to anappropriate group of pagers carried by doctors, nurses and technicians.In addition to the alarm generator, an information communicationscontrol module can be arranged on the medical device so that the sameinformation available to the medical equipment operator can also becommunicated to the master control and display unit or units and to thepagers through a suitable cable connection or through an RF-basedreceiver/transmitter.

The alarm and communications system is designed so that the alarm signalgenerator, the master alarm control and display unit or units, and thepagers and walkie-talkies cannot provide an audio or visual alarm to theparticular patient in trouble. An audio alarm may be utilized inaddition to the visual display at the master control and display unitprovided that the audio alarm sound cannot be heard by the patient. Thealarm signal generator includes a manual call-for-help switch that canbe activated by a person at the bedside to summon additional helpwithout a sensor(s) signal to activate the alarm. Alternatively, thecall-for-help can originate from the pager worn by personnel in need ofassistance. Thus, the nurse can directly page the physician from thepatient's bedside without delay and without alarming the patient. In theevent that incorrect pager numbers are entered by, for example, thebedside, or by the operator of the master alarm control unit, the systemcontains a pager number list to provide immediate feedback to thenurse/operator of an incorrect entry. Users of the system also canaccess the table list by the name of party associated with the desiredpager, in order to look up the correct pager number.

The system may include an additional alarm visual display panel in theroom of the patient hidden from the patient's view. In such case, thealarm visual display would be located so that a lighted panel withlights indicative of a patient problem or equipment malfunction will notbe observable by the monitored patient, but would be visible to hospitaland medical personnel located in the room to indicate a patient monitorwarning or equipment failure. Also, an indicator is provided on theequipment out of the view of the patient to identify the malfunctioningequipment.

The pager is a component of the invention. In accordance with theinvention, an appropriate group of specially designed pagers is utilizedto alert, non-audibly, doctors, nurses and technicians in conjunctionwith the master control and display unit which transmits a coded alarmsignal to the appropriate pager in the appropriate group of pagers. Theappropriate group of pagers has a conventional vibrational annunciator.Also, the appropriate group of pagers contains, in addition to theconventional RF signal receiver and signal processing circuitry, alighted liquid crystal display (LCD) or light emitting diode display(LED) that gives instant information as to the location, patient name,equipment identification and/or other relevant information provideddirectly from the medical equipment, if desired. The coded alarm signalprovides the information which is processed in microprocessor circuitryto actuate an array of lights and/ or liquid crystal or LED elementswhich make up the display face on the pager. The display could alsoinclude a "code blue" indication requiring an immediate response fromall available personnel. A keyboard containing alphanumeric keys andsoft-coded function keys is arranged on the pager to enable the user tocommunicate messages to the master alarm control, and to other pagers.

The pager can also be arranged so that it is worn on the user's wrist inmuch the same manner as a digital wristwatch.

Another important element of the invention is an alarm signal interruptswitch located both on the sensor(s), which is attached to the equipmentat the site of the patient, to the alarm signal generator which isadjacent to the medical equipment and/or on the master alarm controldevice. The alarm signal generator, once activated by a patient problemor equipment defect, will not stop until one of the above-notedinterrupt switches is unlocked and manually actuated, insuring that thepatient will not be inadvertently ignored or forgotten. The interruptswitch can be either a timed switch that returns to a deactivatedposition when timed-out by a suitable timing mechanism or a momentaryswitch that deactivates when released. The status of the interruptswitch and the time period for the interrupt switch may be set by anoperator of the master control unit who has appropriate clearances tounlock the interrupt switch. An interrupt condition and either thetime-out period remaining for that interrupt or the time expired by thatinterrupt may be displayed by the master control unit.

A further feature of the present invention is a walkie-talkiecommunications system that is used in conjunction with the equipmentmonitoring and master control units. The walkie-talkie system isdesigned so that emergency technicians and medical staff can receiveeffective communications from ambulances regarding both the patient'scondition via direct information from medical equipment monitors andaudio messages from emergency personnel (e.g. medical technicians,ambulance drivers, police, fire rescue personnel, etc.) through awalkie-talkie device worn by an emergency personnel.

The rescue walkie-talkie equipment has a privacy function so that allcommunications would occur quietly without causing undue stress to thepatient or others. The walkie-talkie arrangement includes a microphoneand headset piece which are designed to muffle ambient noise levels andto ensure complete privacy of communications. The walkie-talkie designthereby maximizes the patient's privacy by reducing stress created byhearing the communicated information.

It is an object of the invention to provide an improved alarm andcommunications system for patient monitoring and life support equipmentused by patients in pre-hospital, in-hospital and post-hospital settingssuch that the communications and/or alarm resulting from a patient introuble or defective equipment will not be heard or seen by the patientto prevent patient trauma.

It is another object of this invention to provide an improved alarmsystem for critically ill patient monitor and life support equipmentthat alerts only authorized medical personnel according to currenthospital staffing at the moment the alarm is generated without alertingor disturbing any of the patients including the person being monitored.

And yet still another object of this invention is to provide a silentpatient monitor and life support equipment system that eliminates traumato the patient while not reducing the efficiency of the staff to respondappropriately.

In accordance with these and other objects which will be apparenthereinafter, the instant invention will now be described with particularreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic diagram of one embodiment of the presentinvention;

FIG. 2 shows a typical pager display face which may be used with thepresent invention;

FIG. 3 is a schematic diagram of the silent alarm system utilized in thepresent invention;

FIG. 4 is a schematic diagram using a ventilator life support system asan example of the alarm system in accordance with the invention;

FIG. 5 is a schematic block diagram of the master control unit shown inFIG. 1;

FIG. 6 is a perspective view of the walkie-talkie headset arrangementaccording to the present invention;

FIG. 7 is a front detailed view of the microphone mouthpiece of theheadset shown in FIG. 6; and

FIG. 8 is a front view of an alternate pager embodiment according to thepresent invention.

PREFERRED EMBODIMENT OF THE INVENTION

Referring now to the drawings wherein like reference numbers refer tolike parts, and specifically FIG. 1, the present invention is shownschematically comprising an alarm signal pulse generator 12 whichreceives a status output signal from medical equipment and a sensor 10that provides a signal when the equipment sensor(s) indicates thepatient is in trouble or in the event of a malfunction of the equipment.Although conventionally some of the equipment using sensor 10 wouldinclude an audio alarm, applicant's invention would eliminate any typeof audio and/or visual signal that could be heard or seen by the patientattached to the equipment.

The sensor 10 is adapted to be used with pre-hospital equipment such asthose devices employed on ambulances, or at the site of an accident, orin emergency rooms, or in doctor's offices, or in clinics. The sensor(s)can also be attached to equipment used in the hospital, such as patientmonitoring and life support equipment found in the patient's room, suchas in a hospital recovery ward, or life support equipment used in theoperating room. Equipment used in post-hospital settings such as innursing homes, or in hospices or at the patient's home, or in medicaleducational settings are also adapted to be used with the sensor(s). Thecommunications system can also be used in hospital administrationenvironments, such as in the emergency room admissions desk.

The specific types of equipment can include, but are not limited to,defibrillators, oximeters, EKG monitors, EEG monitors, intravenousfeeding devices, ventilators, pulse monitors and any other equipmentused in the above-noted environments.

The sensor 10 is designed to have an adaptable sampling rate based uponthe type of equipment that it is sampling. For example, a ventilator mayrequire a sensor with a very high sampling rate (e.g., every 1-2seconds) while an IV monitor may only be sampled every fifteen minutes.Hence, the sensor 10 can be adjusted to vary the sampling time periodaccordingly. The sensor(s) is also adapted to be connected directly tothe alarm indicator hardware that is found on the specified equipment sothat alarm thresholds identified by a particular equipment manufacturermay be communicated automatically by the sensor 10.

The alarm signal pulse generator 12 takes the status output signal fromthe equipment monitor sensor 10 and converts that signal into a codedpulse that identifies the patient, the room, the ambulance or otherrelevant location information. The equipment type for which sensor 10denotes a problem is also identified along with readings from theequipment.

The output of the alarm signal pulse generator 12 may be communicatedthrough a conventional electric wire or optical cable to the masteralarm control 14 typically located at a nurse's station. Alternatively,communications from generator 12 can be RF-based through conventional RFemergency bands (such as those designated for ambulances) or foremergency medical personnel. If the sensor 10 and generator 12 are usedin a patient's home or at a doctor's office, then the generator 12 canbe connected, for example, through a modem or other communicationsdevices to a phone linked directly to the master control and to thedisplay. Another example of suitable home use for the signal generator12 is in combination with a Halter monitor for sensing EKGlife-threatening arrhythmias, which can be sensed at the master controlunit 14 and communicate to each of an appropriate group of pagers wornby those responsible for this patient. Thus, the present systemencourages the release of patients since they can be monitored at home.

If, for example, a signal generator 12 is located on each ambulanceaffiliated with a single master alarm control and display 14, then aseparate RF band for each ambulance can be assigned to avoidcommunications delays. Individually assigned RF bands can also be usedto designate each patient's room in the hospital.

In addition to signalling the master alarm control, the pulse generatorcan be programmed to simultaneously communicate with the pagers in orderto avoid delays. Thus, if a patient, who is having heart problems, isbeing rushed to the hospital, the EKG information can be communicateddirectly to the master control display while the pulse generator alsoalerts the cardiologist via his/ her pager assigned to the emergencyroom about the incoming patient. If the patient is attended to after thepager is initially activated, the pager can be updated as the patient'scondition changes.

A further function of the pulse generator 12 is it's ability to test theequipment for malfunctions. Tests can be initiated from the master alarmcontrol 14 so that the controller operator can display the equipmentstatus remotely. Thus, to test emergency equipment located in each carof a fleet of ambulances, each RF band can be separately selected by theoperator of the master control 14. The respective pulse generator 12,associated with that identified band is addressed and then in turnresponds to the initiation signal sent from the master control 14 byidentifying the ambulance and associated equipment. The master control14 then signals the pulse generator 12 to activate the emergencyequipment and to test it's condition through sensor 10. The self-testfunction can also be initiated from the pager 16, 18 or 100 or from thetechnician's walkie-talkie. Once tested, equipment status can becommunicated back to the master control 14.

The master control 14 also includes a visual display that providesrelevant information such as patient location, patient condition and thetype of equipment requiring a response. The master control 14 includesan antenna 14a to simultaneously transmit a signal to an appropriategroup of pagers 16 and 18, and 100 (see FIG. 8) each of which haveantennas 16a, 18a and 122, respectively. The appropriate group of pagers16, 18 and 100 has a vibrational annunciator in lieu of or in additionto audio annunciator capabilities so that the wearer, once feeling avibration, will position the pager for visually observing a display facehaving visual indicia. As shown on pager 16 and pager 18, a series oflights may be provided to show room and patient identification thatrequire immediate response. Alternatively, lights can be arranged toindicate other information, such as ambulance number or patient's phonenumber. In addition, other lights can be provided to show what equipmenttype needs immediate response and/or other relevant information.

In addition to pagers, the master control 14 can interact withwalkie-talkie communications devices (see FIGS. 6-7) which are adaptedto receive and transmit voice communications from emergency medicalstaff in conjunction with or completely independent of the medicalequipment alarm discussed above. Communications occur either throughspeaker/microphone 15 which forms part of the control unit 14 or througha headset 80 or any other conventional headset arrangement, whichensures the privacy of communications. The speaker/microphone 15 allowsmultiple individuals to speak through the microphone at the same time.Alternatively, the speaker/microphone 15 can be connected to thehospital intercom system. Further details concerning the headset 80 areset forth below in FIGS. 6-7.

The master control 14 is designed to be programmable by the operator inorder to store information relevant to achieving a prioritized andefficient communication with minimum human intervention so that speed,privacy and efficiency are maximized.

More particularly, the arrangement of the master control 14 is shown inmore detail in FIG. 5. As shown, the master control device is arrangedto provide programmable control for scheduling and prioritizingcommunications in accordance with the staffing realities of thehospital. In order to input current information into the system, theuser operates a keyboard 62. The information provided includes the namesof hospital staff assigned to each patient, to each room, and to eachtype of medical condition as well as the availability of thoseindividuals to respond to emergency calls. Thus, if the doctor assignedto the patient is attending to another emergency, the system flexiblyassigns an alternate doctor who is available and/or who specializes inthe condition indicated by the equipment. Other critical medical data orpersonnel can also be included in the master control 14. For example,the telephone and/or pager number of the original doctor can be inputtedso that the original physician can be notified and consulted. Medicaldata integrated in the device can include all information found on thepatient's chart including laboratory test results. It is contemplatedthat a computerized system that incorporates laboratory test results canform part of the present invention. As an example, the ALERTS systemreported by M. M. Shabot et al. in "Decision Support Alerts for ClinicalLaboratory and Blood Gas Data" in the International Journal of ClinicalMonitoring and Computing 7, pp. 27-31, 1990, would form part of the datawhich can cause alarm conditions to be automatically communicated to themaster control 14 and be communicated to pagers based upon the ALERTSthresholds. Data relating to the ALERTS database could be provided themaster control unit 14 through the hospital database. The pager numberis then automatically called by the device so that communications occurautomatically to appropriate hospital staff with minimal intervention bythe main control operator.

In addition to paging personnel and medical data, the master alarmcontrol device includes prioritizing algorithms which act as messagingtraffic controllers for the system. Thus, in the event that a code bluecondition is communicated, the system interrupts other lower prioritymessages to immediately communicate the "code blue" messages.

The keyboard 62 is connected via a bus 64 in the master control 14 to amemory 66. Any suitable RAM and ROM and/or high speed semiconductormemory device (i.e. such as a scratch-pad or cache memory) can beemployed to quickly retrieve the stored availability information, asneeded. The stored data is then processed by a CPU 68 in order toperform the appropriate logical operations on the stored data (such aschoosing the RF band for the transceiver 70, for interpreting equipmentreadings, for selecting available staff based on a prioritydetermination). The input/output operations of the master control 14 arehandled by the digital I/0 unit 72 which receives digital signals fromthe pulse generator 12 via the cable link 13. Additionally, informationpresented on display for the master control 14 or printed out to anattached printer can also be provided. An audio I/0 unit 74 is used tocontrol information sent to and received from other audio equipment(such as a walkie-talkie headset, or by telephone).

The RF bands available to the master control device may vary dependingupon the particular environment in which the system is placed. If, forexample, the master control unit is used to communicate with ambulances,then the RF band selected for transceiver 70 is an emergency RF band.The selection of RF bands will be controlled through the keyboard 62which causes the transceiver 70 to adjust to a frequency identified bythe operator. Thus, the master control unit can operate at multiplefrequencies, making it flexible. For example, if several master controlunits are employed in the same facility, such as placing one in theoperating room and one in the emergency room and one in the cardiac careunit, then different RF bands can be assigned to different master alarmunits to avoid interference.

In operation, for example, should a patient monitor, such as a pulse orblood pressure monitor, fall below a threshold limit, sensor 10 willprovide a status signal indicating that there is a problem to the alarmsignal pulse generator 12. A coded pulse signal is then prepared andsent to the master alarm control 14 either through the hard-wired cable13 or phone/modem line, or through RF antenna 12a. The master control 14simultaneously displays the information contained in the coded pulsewith regard to room, patient and equipment on a visual display at thenurse's station while the system also transmits simultaneously the codedmessage to the appropriate group of pagers.

As will be described in further detail below, the adaptability of thesystem to communicate over different RF bands is also reflected in thepagers which can be switched from one frequency to another. Accordingly,if a physician works at home, and communicates at home to a modem at onefrequency, he can change his pager RF band to the master controlfrequency for his ward, and then adjust it again to match the band ofthe master alarm unit used in the operating room.

The system can also accommodate a network of master alarm control unitsconnected to one another through a conventional network, such asETHERNET®. Thus, scheduling personnel and medical data information canbe shared between units 14 making the changing needs of the patient andchanging conditions of the hospital more closely attuned to one another.Thus, if a patient is moved from the operating room (OR) to the cardiaccare unit (CCU) and then from the CCU to the general medical recoveryunit, all information pertaining to that patient can be communicatedacross the network 78 to the master alarm control unit 14 responsiblefor that respective area. Thus, for example, the recovery room personnelcan observe the condition of a patient in OR prior to receiving thatpatient in recovery and prepare for that patient's arrival.

Another example of master alarm control unit 14 placement would be toassign a master alarm unit to monitor all signals for a particular typeof equipment. Hence, all ventilator outputs could be handled by one unit14, while all EKG units could be handled by a separate unit 14. Thenumber of units 14 can be adjusted to meet the needs of the ward, of thefloor and of the institution as a whole. The unit 14 can also be placedin doctor's lounges, when appropriate.

Operation of the master alarm control unit 14 can rely on a capablemedical operator who can both insure security, maintain priorities andupdate all information. Operators having different levels of trainingcan be assigned to different master alarm control units 14 or multipleoperators, each having a different level of responsibility, securityclearance and experience can be assigned to a single master controlunit. In the event that multiple emergency conditions are activated forthe same physician, the presence of the operator can ensure that theback-up person with the right expertise can effectively respond to thealarm.

As an example, if the master alarm control unit is used in an operatingroom (OR) setting, then an individual who should, in most instance, be aphysician, may be assigned to simply monitor the status of all of the ORequipment on the display, while each of the physicians in charge ofrespective pieces of equipment wear pagers that are energized when analarm occurs. The operator at the master alarm control in the OR caninterrupt false equipment alarms to avoid unnecessary alarms to thephysicians. Since the display of unit 14 thereby integrates the outputsof all OR equipment, a single individual can oversee the entire physicalcondition of the patient through the unit 14 and also page essentialpersonnel who are outside the OR in the event extra help is needed. Thesystem is also designed to only restrict audible communications ofequipment alarms, but can maintain the normal auditory signalsindicating, for example, that all is well with the patient.

FIG. 2 shows one embodiment of a pager 20 of an appropriate group ofpagers. The pager 20 which includes a plurality of lights 20a thatindicate information silently by illuminating the particular room wherethe patient with life support equipment needing response is located.Likewise, additional lights 20b represent the particular patient withinthe room requiring response. The light indication is augmented through avibration annunciator located on the pager 20.

Referring now to FIG. 3, an alternate embodiment of the invention isshown. The alternate embodiment includes an alarm signal pulse generator32 that receives, as an input, the output signal from patient monitors,which include, but are not limited to, IV feeders, ventilators, EEGdevices, EKG devices, CO₂ measuring devices. The pulse generatorincludes a signal processing unit 32a that can receive an alarm signalfrom a sensor(s) located on any type of equipment indicating that amalfunction or patient problem exists. The signal processor converts thesignal into a coded pulse which is transmitted by cables 30e or bysuitable RF communications to the master control 30, typically locatedat a nurses' station. The master control 30 includes a display face 30bthat comprises lights with room numbers, patient identification and mayinclude an audio microphone/speaker if the master control station islocated far enough away from the patients so that the audio signal couldnot be heard or found disturbing. The display 30b can include the moresophisticated information as shown and described with respect to masteralarm control unit 14 in FIGS. 1 and 5. The master control 30 alsoincludes a pager transmitter which sends an RF signal which is coded tothe appropriate group of pagers 40.

Each of the appropriate group of pagers, in turn, has a visual display40b which may be constructed of a liquid crystal display or lightemitting diode display positioned on one face of the pager. Theannunciator in the pager comprises a kinesthetic vibration caused by avibrator 40c located in the pager. The pager also includes appropriatesignal processing circuitry to drive the display face 40b and thevibrator unit 40c. The pager can also provide information to silentlysummon a specific doctor to a particular location.

Various parts of the system, the master alarm control unit 14, thesensor 10 and the alarm signal pulse generator 32, as shown in FIG. 3,also include an interrupt capability for deactivating the alarm signalsproduced by the system upon activation of the alarm switch. The purposeof the interrupt switch is to block the alarm signals for either aparticular piece of equipment, for an entire room full of equipment orfor even larger areas in the event the person having proper securityclearances believes that an interrupt is necessary. The importance ofthe interrupt switch is it's ability to disarm the alarm for amalfunctioning device, to shut off the alarms relating to all of theequipment attached to a patient (suppose the patient is moved whichtrips all of the monitors attached to him/her) or to disconnect anentire floor of equipment (suppose a technician sets the thresholds forall EKG devices in the hospital too low causing continuous alarms).

Referring to FIG. 3 a main alarm interrupt switch 32d is shown forselectively interrupting signals generated from equipment. The interruptswitch 32d is guarded by a lock (i.e., a number combination, or a usersecurity number if set through the master control) so that the switchcan only be activated when unlocked. The lock is necessary to preventunauthorized individuals from turning off equipment. In addition, thealarm generator signals can only be terminated by physically moving themain switch 32d momentarily located on the alarm signal generatorconnected near the patient bedside to the patient monitor or lifesupport equipment so that the patient must be attended to in order forthe alarm to be turned off.

An interrupt switch can also be placed on the sensor 10 (not shown) sothat it is located physically close or adjacent to the interrupt switchused on the medical equipment itself. As a result, the nurse orphysician can easily turn off the equipment and turn on the interruptswitch without undue inconvenience. In addition, the interrupt switchcan include a lock to safeguard against unauthorized staff fromdisabling equipment. Activating the interrupt switch terminates thecoded pulse signal initiated by the sensor(s) signal for that specificpiece of equipment. The interrupt switch, once released, or turned off,returns the alarm signal pulse generator to its normal activated stateready to respond to a new incoming sensor(s) signal.

The interrupt switch may be a toggle switch that is spring loaded to the"on" position and may include a timer circuit. The interrupt status canalso be displayed on the master alarm control 14.

An interrupt switch with a suitable lock may also be located on themaster alarm control 14 to selectively interrupt individual equipment,all equipment in a patient's room, or all rooms in a given ward. Thealarm control can be programmed so that each higher level of interruptrequires additional locks or higher level security access to the unit14. An individual nurse, for example, may be allowed only to interruptone piece of equipment while only the head nurse or resident on duty candisable an entire ward. The security access element of unit 14 canconsist of any conventional password software lock, or a combination ofmechanical key and software lock elements.

In addition, located in the patient's room out of the vision of thepatient, is a display 32c which could show an attendant in the roomwhich patient and/or equipment demands attention or requires a response.For example, a red light indicating an alarm can be located on theequipment out of the patient's view.

Referring now to FIG. 4, a typical employment of the present inventionis shown. A critically ill bedridden patient 40 is shown connected to aventilator 44 and a sensor 46 which is a device known to provide asignal if the ventilator malfunctions or if there is a breathing problemwith the patient. Although a ventilator is shown in this example,numerous other patient devices can be used individually or can beintegrated together with the present invention.

As an example of a ventilator alarm that could be used with applicant'sinvention, applicant hereby incorporates the disclosure found in U.S.Pat. No. 4,550,726, issued Nov. 5, 1985, to McEwen which describes aventilator monitor that produces an alarm signal if patient breathing isinterrupted. The alarm signal is made to be inaudible for use with thepresent invention. The output alarm signal from the McEwen device would,as an example, be connected and represent sensor 46 in FIG. 4. The alarmsignal generator 48 would then receive a malfunction signal from sensor46 and transmit a generated coded signal to a nurses' station mastercontrol unit 52 located away from the patient. Any monitor, alarm systemand sensor(s) utilized with the present invention will have any existingaudible alarm disengaged. A conventional power supply supplies power tothe alarm signal generator and to the remote master alarm control 52located at the nurses' station.

The alarm signal generator 48 is capable of generating one or moreindividual coded pulses, each of which can be programmed on-site toindividually identify, for example, the type of equipment, the patientlocation, such as a room or ambulance number, and the particular patientwithin a room. A programmable microprocessor alarm signal generator 48can be set to generate a variety of coded pulses depending on aplurality of different inputs into the alarm signal generator. The codedpulses can originate from various different monitors and equipmentsensors that relate to the types of equipment previously discussedherein which may be connected to a single patient or to multiplepatients in a single room.

The master alarm control 52 simultaneously provides a display visuallyat the nurses' station that tells of the immediate problem and displaysthe patient room and equipment requiring response to the alarm signal,and transmits an RF signal to a plurality of pagers 54 having the visualdisplays described above and vibrational annunciators. The transmittedsignals from the master control unit 52 could be coded in such a waythat only particular pagers held by certain personnel would be activatedor appropriate personnel on a particular floor or within a particulararea as described above with reference to FIG. 5. For example,technicians that deal strictly with ventilators may have a certain codethat would not disturb other personnel within a given area. Thus, onlythe appropriate personnel would be paged through their vibrationalannunciators on their pagers. Non-essential or other personnel would notbe disturbed. A high-level emergency or "code blue" signal could also besent for a specific patient monitor or equipment problem.

In addition, the master control unit can be used to monitor the patientcall or help system so that the member unit operator can energize anappropriate group of pagers when the patient call involves an emergency.

In another component to protect the patient, the alarm signal generator48 includes an alarm signal interrupt switch, as previously described,for each piece of equipment in use, which must be manually activated atthe patient's bedside to ensure that the patient or the life supportequipment of the patient is attended to. Therefore, the coded alarmsignal from generator 48 will continue at the nurses, station mastercontrol and display unit 42 and to the pagers 54 until the interruptswitch is momentarily activated at the patient location while theproblem is being corrected.

To show the technology of a pager that includes vibrational output as anannunciator, applicant hereby incorporates the disclosure of U.S. Pat.No. 4,786,889 assigned to the NEC Corporation, issued Nov. 22, 1988.Although the invention described in FIG. 4 relates to a ventilator, allother types of life support equipment and patient monitors can be usedwith the present invention.

Other pagers with or without vibrational annunciators can be used withthe present invention with the addition of the appropriate display.Additionally, those previously described pagers can incorporatetransmitter/receiver devices so that direct two-way communicationsbetween the pagers and the control device 14 are available.

Referring now to FIG. 6, a perspective diagram of a headset microphonearrangement 80 is illustrated. The purpose of this arrangement is toensure that the privacy of verbal communications is maintained in orderto reduce or avoid the panic physiology to the patient and/or others. Anadditional advantage to the headset arrangement is that walkie-talkieusers may conveniently communicate with emergency room staff withouthaving to physically hold the walkie-talkie. In the embodiment shown,the headset is adapted to plug into a walkie-talkie microphone-speakerjack. Alternatively, the walkie-talkie can be incorporated into theheadphone as a single integrated unit. Thus, both hands of the emergencymedical technician are available to treat the patient. Finally, thebaffling on the microphone and earmuffs filter out background noise.

The headset arrangement 80 comprises a tubular headpiece 84 connecting apair of headphones 82. Each of the headphones includes a speaker 83surrounded by a circular cushion 85. Alternatively, the headset speakercan be insertable directly into the ear, without baffling and/or themicrophone can also be arranged without the baffling material. Thecushion can consist of any conventionally used headphone bafflingmaterial such as foam rubber, fabric, or plastic. The cushion surroundsa speaker (not shown) so that outputs of the speaker are only heard bythe telephone wearer and outside noises are filtered out. The leftearphone 87 is designed to swing between a closed position over theuser's left ear (shown by solid lines) or to an open position (shown bydotted lines) allowing the headphone wearer to hear out of one ear. Theswingable arrangement is accomplished by any conventionally known hingeconnection in combination with an appropriate position locking means.

The tubular headpiece 84 extends below the left earphone 87 and connectsto a mouthpiece 90. The shape of the mouthpiece is substantially oval togenerally conform to the shape of the user's open mouth. The mouthpieceincludes an internal microphone 96 (FIG. 7) surrounded by a cushion 92.As in the headphones 82, the cushion 92 provides privacy ofcommunications by completely enclosing the microphone to the user'smouth. In addition, background noise is effectively eliminated so thatcommunications are clearly received.

The mouthpiece 90 is connected to the headpiece 84 through a suitable,arrangement 88 in order that the mouthpiece can be pivoted towards andaway from the user's mouth and adjusted so that it can be placed againstthe user's skin, thus enclosing his or her lips to ensure completeprivacy of communications. As a result, the emergency patient, or otheronlookers, cannot overhear remarks that may cause them undue stress. Anexample of the pivotable connection includes a spring loaded rotatableconnection having detents for locking the microphone in a first positionadjacent the user's mouth and a second position away from the user'smouth (e.g., below his/her chin).

Referring now to FIG. 8, an alternate embodiment of the pager isillustrated. As shown, the pager comprises a wristwatch device 100 whichmay be conveniently worn by a user. The wristwatch pager consist of anLCD-type screen 110 which is subdivided to provide particularinformation about the patient's name 112, location 114, condition 116and automatic equipment information 118. Any information can bedisplayed by the pager including detailed readouts from the medicalequipment.

As a result of reviewing the screen, the wearer is automatically able toascertain the location and condition of the patient and thus quicklyaccess the urgency of the patient's condition and what actions need tobe taken. The pager 100 includes a keyboard 120 which can be used by thepager wearer to send responsive messages back to the hospital through atransceiver linked to antenna 122. The pager can be linked to anycellular network through antenna 122, so that responsive phone calls tothe hospital can be made from any location within the cellular network.

The pager further includes switches 124 and 126. Switch 124 acts toswitch on the display receive mode so that the last displayed message isdisplayed. All messages that are received in a memory can be displayedin sequential fashion and can be sequenced through by multipledepressions. The message send button 126 controls the send mode. Upon afirst depression, it clears the screen and provides an edit mode whichallows the wearer to type in a response and when pressed again, switchesinto a send mode for sending the message through the antenna 122. Thepager thereby automatically allows for silent information basedcommunication with little need for the physician to find a telephone. Asa result, critical time is saved while a maximum amount of informationis automatically sent and retrieved.

In addition to sending return communications to the hospital, the pager100 can also transmit information to other pagers. Thus, if a doctordetermines that he would need assistance on an emergency basis, he maycall other pagers remotely from his own pager and provide aninformational message describing the content of the condition and thelocale of the problem. Special codes can also be set up for automaticmessaging. For example, if a "code blue" condition occurs, a singlebutton can be pressed by the master control 14 to automatically actuateeither an audible, kinesthetic or visual message to the pager.

If a silent mode of operation is desired, the user can activate anannunciator control button 128 which enables the user to select betweenan audible announcement or a vibration annunciation of the message. In ahospital setting, the doctor may want to deactivate any loud audibletones generated by the pager so that only a vibration is sensed. On theother hand, if the audio button 128 is activated, a loud beeping soundwould occur at a particular frequency for standard messages and adifferent frequency for emergency "code blue" type messages.

The invention thus provides a non-audible alarm indicative that acritically ill patient is in need of an immediate response. Only theappropriate doctors, nurses and technical personnel will be immediatelysummoned. The patient will not be startled or even have knowledge thatan alarm has been issued. This will prevent trauma to the patient andwill also aid other patients in the vicinity to prevent them from beingdisturbed by alarms for the same reasons. Other critical problems thussolved by this invention include interfacing personnel through wristband pagers with equipment on sites, interfacing professionals outsideof the hospital with equipment alarms for their patients when on call inaddition to in-house staff, paging people in order to transmit medicalinformation as well as contacting the individual staff who must respondto the communication.

The instant invention has been shown and described herein in what isconsidered to be the most practical and preferred embodiment. It isrecognized, however, that departures may be made therefrom within thescope of the invention and that modifications will occur to a personskilled in the art.

What is claimed is:
 1. A communications system for medical use,comprising:medical equipment associated with a patient; alarm signalgenerator means in communication with aid equipment for generating analarm signal, said alarm signal identifying said equipment and readingsfrom said equipment; control means for receiving said alarm signal andfor displaying indicia relevant to patient location, patientidentification and equipment readings associated with such patient; saidcontrol means having a means for transmitting a pager message to atleast one paging means in the form of an identifying signal, saididentifying signal providing each of said at least one paging means withinformation relevant to said equipment and such patient; and each ofsaid at least one paging means having a visual indicia display, meansfor receiving said pager message, and means for transmitting a responseto said pager message to said control means.
 2. A communication systemaccording to claim 1, wherein each of said at least one paging meansfurther comprises a vibrational annunciator means, each of said at leastone paging means displaying visually relevant information concerningsaid patient and said equipment while also providing a vibrationannunciation.
 3. A communications system according to claim 2, whereinsaid visual indicia display further comprises an illuminated displayscreen for displaying indicia indicative of room, patient and equipmentrelating to the particular alarm signal requiring immediate response. 4.A communications system according to claim 1, wherein each of said atleast one paging means is worn by a user.
 5. A communications systemaccording to claim 1, wherein said control means further comprises:keyinput means for providing messaging information to said control means;memory means for storing said messaging information; processing meansfor processing said messaging information and said alarm signal in orderto prioritize messages and route said messages to appropriate personnel;and transceiver means for communicating said processed messaginginformation.
 6. A communications system according to claim 5, whereinsaid messaging information comprises up-to-date staffing informationrelevant to all patients, said control means further comprises means tosend said processed messaging information to appropriate and availablestaff.
 7. A communications system according to claim 1, wherein saidsystem is used with emergency medical services and ambulance equipmentwhereby said control means receives said alarm signal from emergencymedical equipment used by medical services and ambulances.
 8. Acommunications system according to claim 1, further comprising an audiocommunication means comprising a plurality of walkie-talkies; andacorresponding plurality of portable headsets each adapted to beconnected to a respective walkie-talkie, whereby the privacy ofcommunications between said plurality of walkie-talkies is ensured.
 9. Acommunications system according to claim 8, wherein said plurality ofwalkie-talkies communicates with said control means, said system furthercomprising an additional headset adapted to be connected to said controlmeans.
 10. A communications system according to claim 1, wherein saidsystem is used with equipment at any one or more of a clinic, a doctor'soffice, a hospital, a nursing home and a patient's home.
 11. Acommunications system according to claim 1, wherein said alarm signalgenerator means provides said alarm signal directly to each of said atleast one paging means and to said control means.
 12. A communicationssystem according to claim 1, further comprising:an alarm signalgenerator signal interrupt switch connected to said alarm signalgenerator means and located near said equipment, wherein said alarmsignal, when generated by said alarm signal generator means, continuesuntil said interrupt switch is activated.
 13. A communications systemaccording to claim 1, further comprising a messaging controller meansfor prioritizing said pager message such that a higher priority messagewill interrupt a lower priority message transmitted to each of said atleast one paging means so that the higher priority message will betransmitted to each of said at least one paging means.
 14. Acommunications system for medical use, comprising:a sensor attached tomedical equipment associated with a patient for monitoring the status ofsaid medical equipment; an alarm signal generator in communication withthe sensor for communicating an alarm signal to a remote section; analarm signal generator signal interrupt switch connected to said alarmsignal generator and located near said equipment; wherein said alarmsignal when communicated by said alarm signal generator continues untilsaid interrupt switch is activated, the interrupt switch terminatingsaid alarm signal for a period of time, the alarm signal reactivating atthe end of the period of time if the sensor is in an alarm signalcondition; and a call button for paging medical personnel from thepatient's bedside.
 15. An alarm system comprising:a sensor fordetermining a status of a plurality of conditions of a patient and anoperational status of life support equipment; an alarm signal generatorconnected to said sensor and said alarm signal generator fortransmitting said signals; an alarm controller connected to a signalreceiver and remotely located from said alarm signal generator forgenerating an audio alarm and a visual alarm indicating patient locationin response to said receiver receiving said signals, each alarm beinggenerated at a location remote from the patient; processing meansconnected to said alarm controller for automatically selecting one of aplurality of remote displays for activation; a controller transmitterconnected to said processing means for transmitting a radio frequencysignal to said selected remote display for notification of selectedpersonnel associated with said remote displays that said alarms havebeen generated; and an alarm signal generator signal interrupt switchconnected to said alarm signal generator and located near the bedside ofthe patient wherein said audio and visual alarms when generated by saidalarm controller continue regardless of the receipt of further signalsuntil said interrupt switch is activated.
 16. The alarm system as setforth in claim 15, wherein said alarm signal generator includes a timercircuit connected to said switch to automatically reactivate said alarmsignal after a predetermined time.
 17. The alarm system as set forth inclaim 15, whereinsaid signals generated by said alarm signal generatorinclude a coded electrical pulse indicative of relevant patient andequipment information.
 18. The alarm system set forth in claim 15,wherein said alarm signal generator includes a manually-activated switchfor generating an alarm signal.
 19. The alarm system set forth in claim15, further comprising a visual display unit located in the vicinity ofsaid patient for indicating the status of said patient conditions andsaid equipment status.
 20. A method for communicating medicalinformation comprising:receiving an electrical signal from medicalequipment associated with a patient; generating an alarm signalindentifying said equipment and readings from said equipment;transmitting said alarm signal to a control means, said control meansdisplaying indicia relevant to patient location, patient identificationand equipment readings associated with such patient; transmitting anidentifying signal from said control means to at least one paging meanswith relevant information related to said equipment and such patient forvisual display on an indicia display of each of said at least one pagingmeans; and transmitting a response from any of said at least one pagingmeans to said control means.
 21. An alarm system comprising:a sensor fordetermining a patient's condition; an alarm signal generator connectedto said sensor for generating signals indicative of said patient'scondition and location; an alarm controller connected to a signalreceiver and remotely located from said alarm signal generator forgenerating an alarm indicating patient location in response to saidreceiver receiving said signals, said alarm being generated at alocation remote from the patient; processing means connected to saidalarm controller for automatically selecting at least one or more remotedisplays for activation; a controller transmitter for transmitting aradio frequency signal to said selected remote displays for notifyingselected personnel associated with said remote displays of said alarm;and an alarm signal generator signal interrupt switch connected to saidalarm signal generator and located near the bedside of the patientwherein said alarm, when generated by said alarm controller, continuesregardless of the receipt of further signals until said interrupt switchis activated.